Table of contents

1. A Review of General Chemistry5h 5m
2. Molecular Representations1h 14m
3. Acids and Bases2h 46m
4. Alkanes and Cycloalkanes4h 17m
5. Chirality3h 39m
6. Thermodynamics and Kinetics1h 22m
7. Substitution Reactions1h 48m
8. Elimination Reactions2h 30m
9. Alkenes and Alkynes2h 9m
10. Addition Reactions3h 19m
11. Radical Reactions1h 58m
12. Alcohols, Ethers, Epoxides and Thiols2h 42m
13. Alcohols and Carbonyl Compounds2h 17m
14. Synthetic Techniques1h 26m
15. Analytical Techniques:IR, NMR, Mass Spect7h 3m
16. Conjugated Systems6h 13m
17. Ultraviolet Spectroscopy51m
18. Aromaticity2h 34m
19. Reactions of Aromatics: EAS and Beyond5h 1m
20. Phenols55m
21. Aldehydes and Ketones: Nucleophilic Addition4h 56m
22. Carboxylic Acid Derivatives: NAS2h 51m
23. The Chemistry of Thioesters, Phophate Ester and Phosphate Anhydrides1h 10m
24. Enolate Chemistry: Reactions at the Alpha-Carbon1h 53m
25. Condensation Chemistry2h 9m
26. Amines1h 43m
27. Heterocycles2h 0m
28. Carbohydrates5h 53m
29. Amino Acids4h 20m
30. Peptides and Proteins2h 42m
31. Catalysis in Organic Reactions1h 30m
32. Lipids 2h 50m
33. The Organic Chemistry of Metabolic Pathways2h 52m
34. Nucleic Acids1h 32m
35. Transition Metals6h 14m
36. Synthetic Polymers1h 49m

16. Conjugated Systems

Diels-Alder Reaction

Organic Chemistry

16. Conjugated Systems

Diels-Alder Reaction

Previous problemNext problem

Problem 62

Textbook Question

The product of the Stille coupling reaction (A) tautomerizes in a basic solution to give compound B. B spontaneously converts to C. (a) Propose a structure for A. (b) Suggest a mechanism for the conversion of A to B.

Verified step by step guidance

Step 1: Understand the Stille coupling reaction. The Stille coupling is a palladium-catalyzed cross-coupling reaction between an organotin compound (R-SnR3) and an organic halide (R'-X) to form a new carbon-carbon bond. Identify the possible reactants and the product (A) based on the given information.

Step 2: Propose a structure for compound A. Based on the Stille coupling reaction, determine the structure of A by combining the organic halide and the organotin compound. Ensure the product has the correct connectivity and stereochemistry.

Step 3: Analyze the tautomerization of A to B in a basic solution. Tautomerization typically involves the migration of a proton and the shift of a double bond. Propose a mechanism where a base abstracts a proton from A, leading to the formation of an enolate intermediate, which then rearranges to form compound B.

Step 4: Propose a structure for compound B. Based on the tautomerization mechanism, determine the structure of B. Ensure that the structure reflects the rearrangement of bonds and the new protonation state.

Step 5: Suggest a mechanism for the spontaneous conversion of B to C. Analyze the structure of B and propose a plausible reaction pathway (e.g., intramolecular cyclization, elimination, or rearrangement) that leads to the formation of compound C. Ensure the mechanism is consistent with the chemical properties of B and the stability of C.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above

Play a video:

Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Stille Coupling Reaction

The Stille coupling reaction is a cross-coupling reaction that involves the reaction of an organostannane with an organic halide in the presence of a palladium catalyst. This reaction is widely used in organic synthesis to form carbon-carbon bonds, allowing for the construction of complex molecules. Understanding the nature of the reactants and the conditions required for this reaction is crucial for proposing the structure of compound A.

Tautomerization

Tautomerization is a chemical reaction that involves the interconversion of two isomers, typically involving the relocation of a proton and a shift of a double bond. In the context of the question, the product of the Stille reaction (compound A) undergoes tautomerization in a basic solution to form compound B. Recognizing the structural changes that occur during tautomerization is essential for understanding how to propose the correct structure for A.

Mechanism of Organic Reactions

The mechanism of an organic reaction describes the step-by-step process by which reactants are converted into products, detailing the breaking and forming of bonds. For the conversion of compound A to B, it is important to outline the specific steps involved, including any intermediates and transition states. A clear understanding of reaction mechanisms is vital for accurately suggesting how A transforms into B.

Watch next

Master General Features with a bite sized video explanation from Johnny

Start learning